Add the red pepper flakes, if using, to the butter and swirl them around for about a minute.

Add everything else besides the broth to the pot and salt generously. Cook everything over medium heat, stirring occasionally, until the vegetables have started to soften. This will be about 10 minutes or so.

Add the broth to the pot, bring to a boil, then turn the heat to low. Simmer for about 20 minutes, until the vegetables are all soft.

If you want some chunks in your final soup (like I do), pull out a few spoonfuls of carrot and potato and reserve in a bowl.

Puree the rest of the soup to your desired level of smoothness, either in a blender in batches, or using an immersion blender. (Buy the immersion blender. Just do it).

Taste the soup and add salt and pepper if it needs it. Add the reserved chunks back in to the soup and serve, or chill and serve cold if you’re into that kind of thing. I hear it’s good cold.